Spark plug employed chiefly for supercompression engines



Nov. 23 1926. 1,607,747

M. POGNON I SPARK PLUG EMPLOYED CHIEFLY FOR SUPERCOMPRESSION ENGINES Filed April 19, 1926 Patented Nov. 23, 1926.

UNITED STATES PATENT OFFICE,

MAURICE POGNON, F ESSONNES, FRANCE.

Application filed April 19, 1926, Serial No. 102979. and in France April 21, 1925.

It is well known that one of the greatest drawbacks of the super-compression engines which operate at high speed is the abnormal heating of the internal part of the sparking plug involving spontaneous ignitions, which are very prejudicial to the good operation of the engine.

My invention relates to a special construction of sparking plug, obviating said drawback, and in which an annular groove is provided in the base, in communication on one side with the cylinder by means of a tube and on the other side with the ignition chamber of the plug by, means of two holes,

one of which is situated in front of the sparking head of the central electrode and the other is diametrically opposed relatively to the first. I

The following description together with the appended drawings which are given by way of example sets forth the manner in which the invention is carried into effect.

Fig. 1 is a sectional view of the spark plug.

Fig. 2 is a sectional View on the line XX, Fig. 1.

Fig. 3 is a view analogous to Fig. 1 of a modified construction.

In the threaded portion (l of the base a of the sparking plug is provided an annular groove 6 communicating on one side with the ignition chamber 9 near the sparking head 0 of the insulated electrode 0,, by means of a small hole at, and at the opposite part 5 of chamber 9 by a small hole (Z and on the other side with the cylinder by means of one or several holes or advantageously by means of one or several tubes 6 provided in the I base. The sparking plug further comprises 4 a metallic obturator f separating the ignition chamber 9 of the sparking plug from the cylinder and which is removable. Said obturator is maintained by a pin it passing through the base of the sparking plug, 2'

represents the centre mark for fixing in position the sparking head 0.

It will be noted that the metallic tube e projects at a certain distance under the base The advantages ofthe device are the following:

Firstly, the burnt gases pushed back into the ignition chamber protect the insulation of the plug and the central electrode rod against the heat produced by the explos1on.

Besides, the quantity of fresh gases entering into the ignition chamber being relatively small, the heating produced by the maplosion will be diminished.

Of course, the hole d could be placed in a position somewhat different of that shown by the drawing, and it could even be replaced by several small holes d,. Instead of one single tube 6 two tubes could be disposed on each side of the hole 01, as is shown in Fig. 3.

The example described could of course be modified without departing from the spirit of the invention.

VVhatI claim is:

In a sparking plug specially devised for supercompression engines, an ignition chamber, an obturator separating said chamber from the cylinder, an annular groove provided in the threaded part of the base of the plug, two holes connecting said groove with the ignition chamber, one placed near the sparking head of the central electrode, and the other diametrically opposed to the first, and a tube of communication between the annular groove and the cylinder.

In testimony that I claim the foregoing as my invention, I have signed my name hereto.

MAURICE POGNON. 

